The Reef

Species Spotlight: Fish, Sharks and Rays

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When the exceedingly popular animation Finding Nemo was released, it brought viewers into a world of brightly coloured fish, comparative to the varieties and hues one would see on the actual Great Barrier Reef.

A clownfish in its anemone home, as photographed by Wolcott Henry (National Geographic, n.d.)
A clownfish in its anemone home, as photographed by Wolcott Henry (http://animals.nationalgeographic.com/animals/fish/clown-anemonefish/)

Of the close to 2,000 different species of fish on the reef, perhaps the most famous of them all is the Clown Anemonefish, Amphiprion percula. However, it is the closely-related False Anemonefish, Amphiprion occellaris, who are the stars of Finding Nemo, going on an amazing adventure through hostile waters fraught with danger. Still, perhaps what is more amazing is what happens daily on the great barrier reef on what has come to be known as ‘cleaning stations’.

What seems like a dangerous job for this small cleaner wrasse is actually a common occurrence on many reefs, where predators like this White Tip Reef Shark literally 'park' on the seafloor to be cleaned. (PBase, 1980)
What seems like a dangerous job for this small cleaner wrasse (the yellow fish just below and to the right of  the shark’s dorsal fin) is actually a common occurrence on many reefs, where predators like this White Tip Reef Shark literally ‘park’ on the seafloor to be cleaned. (http://www.pbase.com/rtwrider/image/148322514)

Cleaning stations, prevalent in the Great Barrier Reef and in other reefs around the world, are sites where Cleaner Wrasse (Labroides dimidiatus) and other species of similar wrasse attend to clients of all shapes and sizes who gather for cleaning. Like something out of a scene from yet another animated film about underwater life, cleaning stations are reminiscent of the underwater ‘whale wash’ of Shark Tale, minus the music and not exclusive to whales. Here, all predatory instincts are thrown aside as sharks, rays and all manner of fish arrive to be cleaned by the wrasse. In this mutually beneficial symbiotic relationship (explained in this YouTube video), the fish are cleaned of parasites by the wrasse, who consume these parasites as food.

Continuing with the somehow inevitable links to film, another famous (or perhaps infamous) example of biodiversity on the Great Barrier Reef are the many different kinds of sharks (more than 300 species reside on the Reef, according to Diving Cairns, a dive trip operator located that makes frequent trips to the Great Barrier Reef). Though it is highly likely that none of these sharks will ever attack a boat full of fishermen (or, maybe they will), their reputation undoubtedly precedes them. Ranging from the elusive Reef Sharks (such as the White Tip Reef Shark pictured above) to the dangerous yet strangely alluring Great White Shark (Carcharodon carcharias) of Jaws fame, captured here by a diver on the Great Barrier Reef, sharks never cease to enthrall and intrigue.

A ray photographed by the author at the Melbourne Sea Life Aquarium.
A ray photographed by the author at the Melbourne Sea Life Aquarium.

Closely related to sharks are rays. These encompass the stingray, a specimen of which was involved in the tragic death of Australian icon Steve Irwin, and the majestic Giant Manta Ray (Manta birostris). Capable of growing to a massive seven metres from wingtip to wingtip, Manta rays are only just beginning to be understood by science. One of the two species of Manta rays identified, the Giant Manta is pelagic, meaning that they often cross oceans in extended trips of incredible distances. This nature makes them hard to monitor as an IUCN Red List Vulnerable species. However, their popularity with divers, given their docile nature (and the fact that they seem pretty OK with being approached, as seen in this video) is seen as encouraging in helping to preserve this awesome creature from extinction.